The present invention relates to building construction and, more particularly, to structural members for connection to building panels which are then used to construct walls, floors, roofs and the like.
Over the years, various methods have been developed to manufacture low-cost housing and other buildings that are relatively quick and simple to construct, without sacrificing the structural integrity of the finished structure. One such method employs pre-fabricated building panels, usually constructed from concrete, to form the walls, floors and roofs of the building structure. Such building panels can be constructed on or off-site and then moved into a specific position to form the walls, floors and roofs of the building structure. These pre-fabricated panels are reinforced and joined to each other by metal studs and joists embedded in the panels.
A typical prefabricated building panel has numerous parallel metal studs and joists embedded in a planar concrete panel. The concrete panel is usually 1.5 to 2 inches thick, although its thickness can vary depending on the particular application and the strength requirements needed. For increased strength, a reinforcing material, such as polypropylene-type fibers, steel fibers or mesh, often is embedded within the concrete panel. The metal studs, usually common C-shaped channel members, are placed parallel to each other, with their edges on or in the newly poured concrete panel. When the concrete hardens, the metal studs are permanently bonded to the panel, and the whole panel is thereafter transferred into a position to form part of the wall, floor or roof of a building.
It is generally recognized that the overall strength of a prefabricated building panel is, in large part, dependent upon the integrity of the bond that is created between the metal stud and the concrete panel, after the concrete has hardened. For example, a stud edge surface in simple contact with the surface of the concrete panel results in a relatively weak bond and, therefore, a relatively weak panel. Accordingly, it has become a common technique to provide projections on the edge of the stud that extend into the wet concrete, thereby securely anchoring the stud to the concrete panel when the concrete hardens.
By way of example, projections can be provided directly on the flange of a metal stud to anchor the stud to the panel. In one known method, the metal stud is shaped like a common "C" channel and has a planar central web and a pair of substantially perpendicular edge flanges. However, one edge flange has a series of spaced, longitudinally shaped cut-outs along its length, thereby permitting the cut-out portion of the edge flange to bend upwards and form a projection which can be embedded within the concrete material of the panel. A reinforcing mesh or the like can be mechanically attached to each projection so that the mesh is positioned at the proper depth within the panel.
Alternatively, a specially manufactured stud can be fabricated, in which one of the edge flanges has an increased length. This edge flange can be bent upwards in an appropriate fashion to provide a continuous projection for embedding within the concrete panel.
However, pre-fabricated building panels of the type described above are not without several known drawbacks. For example, the studs must be either specially modified (as in the case of the cut-outs on the edge flange to form projections) or specially manufactured (as in the case of edge flanges with increased length to form a continuous protrusion). This adds to the cost of labor and materials of the finished panel, since common, off-the-shelf C-shaped studs cannot be used. Moreover, since the stud must be specially modified or manufactured at an off-site manufacturing facility, the studs are not readily susceptible to further modifications or adjustments to meet unusual or special needs which may arise in the field.
In addition, as noted above, the projections on some studs are made out of material removed from the edge flange of the stud itself, thus weakening the stud in that area. Further, these projections are limited in size, shape and number because they are formed from the limited material provided by the width of the edge flange. A further problem associated with the studs described above is the relatively straight shape of the projections. Generally, projections having an angled or hooked shape will embed in the concrete more securely and provide a stronger bond. While the projections of known studs have a small portion which can be bent to form an angle, the relatively small size of the bent portion tends to limit its effectiveness.
Likewise, there is an existing and reoccurring problem of crazing or cracking longitudinally along the knife-like projection of the deformed studs currently being used to create site-cast building panels. Problems also have existed with the present methods that have been used to provide lateral bracing of the studs and joists of the building panels. The present methods of lateral bracing are relatively time consuming and undesirably add to the overall material and labor costs. There also is some doubt as to the effectiveness of these prior bracing methods.
Accordingly, there has existed a definite need for a structural member which provides a secure connection to a building panel, without requiring specially modified or manufactured studs or the like. There further has existed a need for a reinforcing member for use with a standard structural member, such as a stud or a joist, that both reinforces the structural member and securely connects it to the building panel. There also has existed a need for a better means for bracing the structural members connected to the building panel. The present invention satisfies these needs and provides further related advantages.